linq distinct by id examples

Example 1: C# .NET Core linq Distinct

var distinctUsers = allUsers
    .GroupBy(x => x.UserId)
    .Select(x => x.First())
    .ToList();

Example 2: c# distinct comparer multiple properties

List<Person> distinctPeople = allPeople
  .GroupBy(p => new {p.PersonId, p.FavoriteColor} )
  .Select(g => g.First())
  .ToList();